/****************************************************************************
**
** This file is part of the KD Chart library.
**
** SPDX-FileCopyrightText: 2001 Klarälvdalens Datakonsult AB, a KDAB Group company <info@kdab.com>
**
** SPDX-License-Identifier: MIT
**
****************************************************************************/

#include "kdganttforwardingproxymodel.h"

#include <QStringList>
#include <cassert>

using namespace KDGantt;

typedef QAbstractProxyModel BASE;

/*! Constructor. Creates a new ForwardingProxyModel with
 * parent \a parent
 */
ForwardingProxyModel::ForwardingProxyModel(QObject *parent)
    : BASE(parent)
{
}

ForwardingProxyModel::~ForwardingProxyModel()
{
}

/*! Converts indexes in the source model to indexes in the proxy model */
QModelIndex ForwardingProxyModel::mapFromSource(const QModelIndex &sourceIndex) const
{
    if (!sourceIndex.isValid())
        return QModelIndex();
    assert(sourceIndex.model() == sourceModel());

    // Create an index that preserves the internal pointer from the source;
    // this way KDDataConverterProxyModel preserves the structure of the source model
    return createIndex(sourceIndex.row(), sourceIndex.column(), sourceIndex.internalPointer());
}
#ifdef __GNUC__
#if __GNUC__ > 3
#define ATTRIBUTE __attribute__((__may_alias__))
#endif
#else
#define ATTRIBUTE
#endif
namespace {
// Think this is ugly? Well, it's not from me, it comes from QProxyModel
struct ATTRIBUTE KDPrivateModelIndex
{
    int r, c;
    void *p;
    const QAbstractItemModel *m;
};
}

/*! Converts indexes in the proxy model to indexes in the source model */
QModelIndex ForwardingProxyModel::mapToSource(const QModelIndex &proxyIndex) const
{
    if (!proxyIndex.isValid())
        return QModelIndex();
    assert(proxyIndex.model() == this);
    // So here we need to create a source index which holds that internal pointer.
    // No way to pass it to sourceModel()->index... so we have to do the ugly way:
    QModelIndex sourceIndex;
    auto *hack = reinterpret_cast<KDPrivateModelIndex *>(&sourceIndex);
    hack->r = proxyIndex.row();
    hack->c = proxyIndex.column();
    hack->p = proxyIndex.internalPointer();
    hack->m = sourceModel();
    assert(sourceIndex.isValid());
    return sourceIndex;
}

/*! Sets the model to be used as the source model for this proxy.
 * The proxy does not take ownership of the model.
 * \see QAbstractProxyModel::setSourceModel
 */
void ForwardingProxyModel::setSourceModel(QAbstractItemModel *model)
{
    if (sourceModel())
        sourceModel()->disconnect(this);
    BASE::setSourceModel(model);

    if (!model)
        return;

    connect(model, &QAbstractItemModel::modelAboutToBeReset, this, &ForwardingProxyModel::sourceModelAboutToBeReset);
    connect(model, &QAbstractItemModel::modelReset, this, &ForwardingProxyModel::sourceModelReset);
    connect(model, &QAbstractItemModel::layoutAboutToBeChanged, this, &ForwardingProxyModel::sourceLayoutAboutToBeChanged);
    connect(model, &QAbstractItemModel::layoutChanged, this, &ForwardingProxyModel::sourceLayoutChanged);

    connect(model, &QAbstractItemModel::dataChanged,
            this, &ForwardingProxyModel::sourceDataChanged);

    connect(model, &QAbstractItemModel::columnsAboutToBeInserted,
            this, &ForwardingProxyModel::sourceColumnsAboutToBeInserted);
    connect(model, &QAbstractItemModel::columnsInserted,
            this, &ForwardingProxyModel::sourceColumnsInserted);
    connect(model, &QAbstractItemModel::columnsAboutToBeRemoved,
            this, &ForwardingProxyModel::sourceColumnsAboutToBeRemoved);
    connect(model, &QAbstractItemModel::columnsRemoved,
            this, &ForwardingProxyModel::sourceColumnsRemoved);

    connect(model, &QAbstractItemModel::rowsAboutToBeInserted,
            this, &ForwardingProxyModel::sourceRowsAboutToBeInserted);
    connect(model, &QAbstractItemModel::rowsInserted,
            this, &ForwardingProxyModel::sourceRowsInserted);
    connect(model, &QAbstractItemModel::rowsAboutToBeRemoved,
            this, &ForwardingProxyModel::sourceRowsAboutToBeRemoved);
    connect(model, &QAbstractItemModel::rowsRemoved,
            this, &ForwardingProxyModel::sourceRowsRemoved);
}

/*! Called when the source model is about to be reset.
 * \sa QAbstractItemModel::modelAboutToBeReset()
 */
void ForwardingProxyModel::sourceModelAboutToBeReset()
{
    // The matching signal is emitted be reset()
}

/*! Called when the source model is reset
 * \sa QAbstractItemModel::modelReset()
 */
void ForwardingProxyModel::sourceModelReset()
{
    // qDebug() << "ForwardingProxyModel::sourceModelReset()";
    beginResetModel();
    endResetModel();
}

/*! Called just before the layout of the source model is changed.
 * \sa QAbstractItemModel::layoutAboutToBeChanged()
 */

void ForwardingProxyModel::sourceLayoutAboutToBeChanged()
{
    // qDebug() << "ForwardingProxyModel::sourceLayoutAboutToBeChanged()";
    Q_EMIT layoutAboutToBeChanged();
}

/*! Called when the layout of the source model has changed.
 * \sa QAbstractItemModel::layoutChanged()
 */
void ForwardingProxyModel::sourceLayoutChanged()
{
    // qDebug() << "ForwardingProxyModel::sourceLayoutChanged()";
    beginResetModel();
    endResetModel();
}

/*! Called when the data in an existing item in the source model changes.
 * \sa QAbstractItemModel::dataChanged()
 */
void ForwardingProxyModel::sourceDataChanged(const QModelIndex &from, const QModelIndex &to)
{
    // qDebug() << "ForwardingProxyModel::sourceDataChanged("<<from<<to<<")";
    Q_EMIT dataChanged(mapFromSource(from), mapFromSource(to));
}

/*! Called just before columns are inserted into the source model.
 * \sa QAbstractItemModel::columnsAboutToBeInserted()
 */
void ForwardingProxyModel::sourceColumnsAboutToBeInserted(const QModelIndex &parentIdx,
                                                          int start,
                                                          int end)
{
    beginInsertColumns(mapFromSource(parentIdx), start, end);
}

/*! Called after columns have been inserted into the source model.
 * \sa QAbstractItemModel::columnsInserted()
 */
void ForwardingProxyModel::sourceColumnsInserted(const QModelIndex &parentIdx, int start, int end)
{
    Q_UNUSED(parentIdx);
    Q_UNUSED(start);
    Q_UNUSED(end);
    endInsertColumns();
}

/*! Called just before columns are removed from the source model.
 * \sa QAbstractItemModel::columnsAboutToBeRemoved()
 */
void ForwardingProxyModel::sourceColumnsAboutToBeRemoved(const QModelIndex &parentIdx,
                                                         int start,
                                                         int end)
{
    beginRemoveColumns(mapFromSource(parentIdx), start, end);
}

/*! Called after columns have been removed from the source model.
 * \sa QAbstractItemModel::columnsRemoved()
 */
void ForwardingProxyModel::sourceColumnsRemoved(const QModelIndex &parentIdx, int start, int end)
{
    Q_UNUSED(parentIdx);
    Q_UNUSED(start);
    Q_UNUSED(end);
    endRemoveColumns();
}

/*! Called just before rows are inserted into the source model.
 * \sa QAbstractItemModel::rowsAboutToBeInserted()
 */
void ForwardingProxyModel::sourceRowsAboutToBeInserted(const QModelIndex &parentIdx, int start, int end)
{
    beginInsertRows(mapFromSource(parentIdx), start, end);
}

/*! Called after rows have been inserted into the source model.
 * \sa QAbstractItemModel::rowsInserted()
 */
void ForwardingProxyModel::sourceRowsInserted(const QModelIndex &parentIdx, int start, int end)
{
    Q_UNUSED(parentIdx);
    Q_UNUSED(start);
    Q_UNUSED(end);
    endInsertRows();
}

/*! Called just before rows are removed from the source model.
 * \sa QAbstractItemModel::rowsAboutToBeRemoved()
 */
void ForwardingProxyModel::sourceRowsAboutToBeRemoved(const QModelIndex &parentIdx, int start, int end)
{
    beginRemoveRows(mapFromSource(parentIdx), start, end);
}

/*! Called after rows have been removed from the source model.
 * \sa QAbstractItemModel::rowsRemoved()
 */
void ForwardingProxyModel::sourceRowsRemoved(const QModelIndex &parentIdx, int start, int end)
{
    Q_UNUSED(parentIdx);
    Q_UNUSED(start);
    Q_UNUSED(end);
    endRemoveRows();
}

/*! \see QAbstractItemModel::rowCount */
int ForwardingProxyModel::rowCount(const QModelIndex &idx) const
{
    return sourceModel()->rowCount(mapToSource(idx));
}

/*! \see QAbstractItemModel::columnCount */
int ForwardingProxyModel::columnCount(const QModelIndex &idx) const
{
    return sourceModel()->columnCount(mapToSource(idx));
}

/*! \see QAbstractItemModel::index */
QModelIndex ForwardingProxyModel::index(int row, int column, const QModelIndex &parent) const
{
    return mapFromSource(sourceModel()->index(row, column, mapToSource(parent)));
}

/*! \see QAbstractItemModel::parent */
QModelIndex ForwardingProxyModel::parent(const QModelIndex &idx) const
{
    return mapFromSource(sourceModel()->parent(mapToSource(idx)));
}

/*! \see QAbstractItemModel::setData */
bool ForwardingProxyModel::setData(const QModelIndex &index, const QVariant &value, int role)
{
    // qDebug() << "ForwardingProxyModel::setData( " << index<<value<< role<<")";
    return sourceModel()->setData(mapToSource(index), value, role);
}

QMimeData *ForwardingProxyModel::mimeData(const QModelIndexList &indexes) const
{
    QModelIndexList source_indexes;
    for (int i = 0; i < indexes.count(); ++i)
        source_indexes << mapToSource(indexes.at(i));
    return sourceModel()->mimeData(source_indexes);
}

bool ForwardingProxyModel::dropMimeData(const QMimeData *data, Qt::DropAction action, int row, int column, const QModelIndex &parent)
{
    if ((row == -1) && (column == -1))
        return sourceModel()->dropMimeData(data, action, -1, -1, mapToSource(parent));
    int source_destination_row = -1;
    int source_destination_column = -1;
    QModelIndex source_parent;
    if (row == rowCount(parent)) {
        source_parent = mapToSource(parent);
        source_destination_row = sourceModel()->rowCount(source_parent);
    } else {
        QModelIndex proxy_index = index(row, column, parent);
        QModelIndex source_index = mapToSource(proxy_index);
        source_destination_row = source_index.row();
        source_destination_column = source_index.column();
        source_parent = source_index.parent();
    }
    return sourceModel()->dropMimeData(data, action, source_destination_row, source_destination_column, source_parent);
}

QStringList ForwardingProxyModel::mimeTypes() const
{
    return sourceModel()->mimeTypes();
}

Qt::DropActions ForwardingProxyModel::supportedDropActions() const
{
    return sourceModel()->supportedDropActions();
}

#include "moc_kdganttforwardingproxymodel.cpp"
